Variable Inertia Charge System (VICS) Check Valve (One-Way)

Remove VICS check valve (one-way). Blow air into port "A" and ensure air flows from port "B". See Fig 1. Blow air into port "B". Air should not flow from port "A". If airflow is not as specified, replace VICS check valve (one-way).

Fig 1: Identifying Check Valve (One-Way or Delay) - Miata, Protege & Protege5

Courtesy of MAZDA MOTORS CORP.